I would say it is a relay.
The box is the coil which has 400 Ohm resistance and 1mH inductance
I don't know why they specified the inductance of the coil, I can't imagine it's really important, probably it's just what they had.
Since said coil is shown as powered from 12v, and we know it's 400R, it will be around 25-30mA when the transistor below it is saturated.
On Mon, Jan 2, 2017 at 4:35 PM, Rob roomberg@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:What is the component labeled K1 1mH 400 ohm on the right side of this
schematic?
http://www.learnmorsecode.com/ laminator/gbc/pp330.jpg
